With people's increasing attention being paid on network security, the verification code technology is developing more and more rapidly. A verification code takes a variety of forms such as a digital verification code, an alphabet verification code, a graphic verification code and a combination thereof and so on, wherein the digital verification code is a form with simple principles and broad applications. The verification code generally presents in a security verification part. For security needs to prevent brute force attacks, the verification code is often used to verify whether a user behavior is authentic.
In a mobile era, receiving a digital verification code by a short message is a very common and effective way for verifying the validity of a cell phone number or the authenticity of a user. When a user needs to fill a digital verification code in a short message into a certain application of a computer or a cell phone, the user needs to remember this digital verification code in a short time and therefore may have to check the short message for several times.
In prior arts, each bit of a digital verification code is selected randomly from the Arabic digitals 0-9 and the selected result is generated as a verification code. The generated code is typically a combination of digitals, each bit of which is different and which is out of order. However, for such a verification code, it is very difficult for the user to remember it in a short time and then enter it correctly once.